CXCL8 and rheumatoid arthritis: The genes which were selected for the models are not unknown: LXN is known to be upregulated in early OA [53] and not only as part of the inflammatory response but also influencing the perception of pain [54]; several CXCL genes (chemokines) have been shown to be upregulated at RA, also CXCL8 [11, 12]; MAB21L2 is upregulated especially in OA [55]; about the RP11-* genes less is known as these labels are still their original clone ID [56].